you pick door 1. the host does his thing. now the situation is: if it was behind door 1, you win by not switching. if it was behind door 2 or 3, switching wou

you pick door 1. the host does his thing. now the situation is: if it was behind door 1, you win by not switching. if it was behind door 2 or 3, switching would win. seems intuitive to me.